It is known to use optoelectronic sensor devices as dirt detectors. Usually, a sensor device of this kind is comprised of a radiation-conducting sensor body that contains at least one radiation transmitter that projects test light in the form of a parallel radiation beam through a test surface provided on the sensor body to at least one radiation receiver. Dirt deposited on the test surface influences the intensity of the radiation received by the radiation receiver. Patent application DE 197 13 910 C1 has disclosed a sensor device in which the production and focusing of the parallel test light occurs inside the sensor body. In order to achieve a low structural height, the test light is totally reflected against the circumference surface of the sensor body; at the same time, the circumference surface is designed so that the radiation beam emitted by the radiation transmitter is sufficiently focused and is conveyed to the radiation receiver. The transmitter unit and the receiver unit must therefore be adjusted to a correspondingly precise degree when they are mounted in the sensor device.
The object of the invention is to produce a sensor device that permits a compact design while having low requirements with regard to installation-related tolerances, and to disclose a use of the sensor device as well as a vehicle light.